摘要：
Self-incompatibility (SI) poses a significant reproductive barrier, severely impacting the yield, quality, and economic value of Camellia oleifera. In this study, methyl jasmonate (MeJA) was employed as an exogenous stimulus to alleviate SI in C. oleifera. The research findings revealed that an exogenous dose of 1000 μmol·L(-1) MeJA enhanced the germination and tube growth of C. oleifera self-pollen and greatly improved ovule penetration (18.75%) and fertilization (15.81%), ultimately increasing fruit setting (18.67%). It was discovered by transcriptome analysis that the key genes (CAD, C4H) involved in the lignin production process exhibited elevated expression levels in self-pistils treated with MeJA. Further analysis showed that the lignin concentration in the MeJA-treated pistils was 31.70% higher compared with the control group. As verified by pollen germination assays in vitro, lignin in the appropriate concentration range could promote pollen tube growth. Gene expression network analysis indicated that transcription factor bHLH may be pivotal in regulating lignin biosynthesis in response to MeJA, which in turn affects pollen tubes. Further transient knockdown of bHLH (Co_33962) confirmed its important role in C. oleifera pollen tube growth. In summary, the application of MeJA resulted in the stimulation of self-pollen tube elongation and enhanced fruit setting in C. oleifera, which could be associated with the differential change in genes related to lignin synthesis and the increased lignin content.
摘要：
<jats:title>ABSTRACT</jats:title><jats:p>Achieving seedlessness in citrus varieties is one of the important objectives of citrus breeding. Male sterility associated with abnormal pollen development is an important factor in seedlessness. However, our understanding of the regulatory mechanism underlying the seedlessness phenotype in citrus is still limited. Here, we determined that the miR159a‐<jats:italic>DUO1</jats:italic> module played an important role in regulating pollen development in citrus, which further indirectly modulated seed development and fruit size. Both the overexpression of csi‐miR159a and the knocking out of <jats:italic>DUO1</jats:italic> in Hong Kong kumquat (<jats:italic>Fortunella hindsii</jats:italic>) resulted in small and seedless fruit phenotypes. Moreover, pollen was severely aborted in both transgenic lines, with arrested pollen mitotic I and abnormal pollen starch metabolism. Through additional cross‐pollination experiments, <jats:italic>DUO1</jats:italic> was proven to be the key target gene for miR159a to regulate male sterility in citrus. Based on DNA affinity purification sequencing (DAP‐seq), RNA‐seq, and verified interaction assays, <jats:italic>YUC2</jats:italic>/<jats:italic>YUC6, SS4</jats:italic> and <jats:italic>STP8</jats:italic> were identified as downstream target genes of <jats:italic>DUO1</jats:italic>, those were all positively regulated by <jats:italic>DUO1</jats:italic>. In transgenic <jats:italic>F. hindsii</jats:italic> lines, the miR159a‐<jats:italic>DUO1</jats:italic> module down‐regulated the expression of <jats:italic>YUC2</jats:italic>/<jats:italic>YUC6</jats:italic>, which decreased indoleacetic acid (IAA) levels and modulated auxin signaling to repress pollen mitotic I. The miR159a‐<jats:italic>DUO1</jats:italic> module reduced the expression of the starch synthesis gene <jats:italic>SS4</jats:italic> and sugar transport gene <jats:italic>STP8</jats:italic> to disrupt starch metabolism in pollen. Overall, this work reveals a new mechanism by which the miR159a‐<jats:italic>DUO1</jats:italic> module regulates pollen development and elucidates the molecular regulatory network underlying male sterility in citrus.</jats:p>
摘要：
The fruit of Camellia oleifera has a wide range of industrial applications, but the self-incompatibility (SI) limits the fruit yield and restricts the development of C. oleifera industry. How to erase the SI of C. oleifera to increase fruit set is an urgent problem to be solved. In this study, tannase (TA), plant growth regulators, antioxidants, nitric oxide inhibitors, and epigenetic modification substances were used to treat self-pollinated C. oleifera, and the results showed that 5 g & sdot;L-1 TA could significantly improve the self-pollinated fruit setting rate by 16.06-22.33%. Fluorescence microscopy and paraffin section observation showed that TA treatment promoted the growth of self-pollen tube in C. oleifera, and significantly increased the ovule penetration (18.38%) and fertilization (16.18%). Pistil transcriptome analysis suggested that genes related to shikimic acid, gallic acid, phenylpropanoid, and flavonoid were significantly differentially expressed with the growth promotion of self-pollen tubes. TA treatment significantly increased flavonoids by 0.56 mg & sdot;g-1 and total polyphenols by 0.45 mg & sdot;g-1 in C. oleifera pistils compared to control, respectively, which was consistent with the trend of up-regulation of related gene expression. In addition, the results of the pollen in vitro germination test showed that high concentrations of shikimic acid, gallic acid, and epicatechin promoted the growth of pollen tubes within a certain concentration range. Cytoscape visualization suggested that MYBs, WRKYs, C2H2s, and other transcription factors interacted with the above key genes in response to TA treatment to regulate the accumulation of total polyphenols and flavonoids and the growth of self-pollen tubes, ultimately increasing fruit set. This study provides a new comprehensive understanding of exogenous TA on cell morphology, physiological changes, and gene expression regulation in C. oleifera, and provides useful references for the wide application of TA and the breaking of SI in other plants.
摘要：
Slow-release fertilizers have been known to boost crop yields, but their high cost and slow degradation make them less practical for use. In this study, oyster shell (OS) was modified by mechanical ball milling with monosodium glutamate (MSG) wastewater as an activator to prepare activated oyster shell (AOS) with an average particle size of 32.7 nm. Compared to natural oyster shell (NOS), the AOS increased water-soluble Ca by 22 times, expanded the average desorption pore size by 155 %, enhanced the specific surface area by 9 times, and improved the total pore volume by 1587 %. AOS was mixed with traditional fertilizers and extruded to develop a new type of activated oyster-based slow-release compound fertilizer (AOF). Physical effects mainly controlled the slow-release ability of AOF. AOS formed vaterite with a large peak shape, high strength, and well-defined crystal structure, providing more binding sites for NH4+, HPO42- , K+, Ca2+ and Mg2+. In addition, AOS was rich in Ca-OH and Mg-OH, which increased the potential for ligand exchange with fertilizer ions, which further improved the chemical slow-release properties of AOF. The AOF continuously releases N, P, K, Ca, and Mg nutrients over a period exceeding 70 days. The nutrient release behavior in AOF was accurately described by the logistic equation, the Elovich equation, and the parabolic diffusion equation. AOF increased the dry weight of green plum by 190 % and the yield by 61 %. The AOF prepared in this study proved to be an innovative and environmentally sustainable slow-release fertilizer.
摘要：
Self-incompatibility (SI) is one of the main reasons leading to the low fruit set of Camellia oleifera and limiting the yield of Camellia oil. It is important to uncover the molecular mechanism of SI for guiding production. Accurate quantification of the expression level of SI determinants is essential, which requires qRT-PCR technology and appropriate reference genes. However, the screening of SI-related reference genes in C. oleifera has not been reported. In this study, multiple transcriptome data were innovatively integrated and candidate reference genes of SI were systematically and rapidly screened in C. oleifera. TIF3H1 was selected as the most stable gene expressed in pistillate tissues of C. oleifera under different pollination treatments based on the comprehensive evaluation using qRT-PCR and statistical algorithms of geNorm, NormFinder, BestKeeper, and RefFinder. The expression of SI-related genes of C. oleifera validated the stability of TIF3H1 as the reference gene. Using TIF3H1 as the reference gene, the expression of the potential SI determinants in compatible and incompatible pistils was accurately quantified, and the high expression of the homologous gene of pectin methylesterase (PME) in incompatible pistils suggested its positive effect on SI of C. oleifera. The identification of TIF3H1 as the reliable reference gene guarantees more accurate qRT-PCR quantification for the study of the SI of C. oleifera, laying a foundation for identifying determinants of SI and exploring its molecular mechanism.
期刊：
FRONTIERS IN PLANT SCIENCE,2023年14:1328990 ISSN：1664-462X
作者机构：
[Heping Cao] United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, United States;[Wenfang Gong; Deyi Yuan] Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Central South University of Forestry and Technology, China;[Jun Rong] School of Life Sciences, Nanchang University, China
作者机构：
[Hou, Jinbo; Yuan, Deyi] Cent South Univ Forestry & Technol, Sch Forestry, Changsha 410004, Peoples R China.;[Pugazhendhi, Arivalagan] Van Lang Univ, Sch Engn & Technol, Emerging Mat Energy & Environm Applicat Res Grp, Ho Chi Minh City, Vietnam.;[Sindhu, Raveendran] T K M Inst Technol, Dept Food Technol, Kollam 691505, Kerala, India.;[Vinayak, Vandana] Dr Harisingh Gour Cent Univ, Sch Appl Sci, Diatom Nano Engn & Metab Lab DNM, Sagar 470003, Madhya Pradesh, India.;[Thanh, Nguyen Chi] Ho Chi Minh City Univ Technol & Educ, Fac Appl Sci, Ho Chi Minh City 70000, Vietnam.
通讯机构：
[Nguyen Thuy Lan Chi; Deyi Yuan] S;Emerging Materials for Energy and Environmental Applications Research Group, School of Engineering and Technology, Van Lang University, Ho Chi Minh City, Viet Nam. Electronic address: pugal.
摘要：
In a desperate attempt to find organic alternatives to synthetic fertilizers, agricultural scientists are increasingly using biochar as a soil amendment. Using chemical fertilizers results in enormous financial burdens and chronic health problems for plants and soils. Global concerns have also increased over the prolonged consumption of foods grown with artificial fertilizers and growth promotors. This adversely affects the environment and the welfare of humans, animals, and other living organisms. This way, organic biofertilizers have established a sustainable farming system. In such a context, biochar is gaining much attention among scientists as it may improve the overall performance of plants; in particular, crops have been optimistically cultivated with the addition of various sources. Field experiments have been conducted with multiple plant-based biochars and animal manure-based biochar. Plants receive different essential nutrients from biochar due to their physicochemical properties. Despite extensive research on biochar's effects on plant growth, yield, and development, it is still unknown how biochar promotes such benefits. Plant performance is affected by many factors in response to biochar amendment, but biochar's effect on nutrient uptake is not widely investigated. We attempted this review by examining how biochar affects nutrient uptake in various crop plants based on its amendment, nutrient composition, and physicochemical and biological properties. A greater understanding and optimization of biochar-plant nutrient interactions will be possible due to this study.
摘要：
Camellia oleifera is an important woody oil species in China. Its seed oil has been widely used as a cooking oil. Seed size is a crucial factor influencing the yield of seed oil. In this study, the horizontal diameter, vertical diameter and volume of C. oleifera seeds showed a rapid growth tendency from 235 days after pollination (DAP) to 258 DAP but had a slight increase at seed maturity. During seed development, the expression of genes related to cell proliferation and expansion differ greatly. Auxin plays an important role in C. oleifera seeds; YUC4 and IAA17 were significantly downregulated. Weighted gene co-expression network analysis screened 21 hub transcription factors for C. oleifera seed horizontal diameter, vertical diameter and volume. Among them, SPL4 was significantly decreased and associated with all these three traits, while ABI4 and YAB1 were significantly increased and associated with horizontal diameter of C. oleifera seeds. Additionally, KLU significantly decreased (2040-fold). Collectively, our data advances the knowledge of factors related to seed size and provides a theoretical basis for improving the yield of C. oleifera seeds.
作者机构：
[Hou, Jinbo; Yuan, Deyi] Cent South Univ Forestry & Technol, Sch Forestry, Changsha 410004, Peoples R China.;[Pugazhendhi, Arivalagan] Van Lang Univ, Sch Engn & Technol, Emerging Mat Energy & Environm Applicat Res Grp, Ho Chi Minh City, Vietnam.;[Phuong, Tran Nhat] Van Lang Univ, Fac Med, Ho Chi Minh City, Vietnam.;[Thanh, Nguyen Chi] Ho Chi Minh City Univ Technol & Educ, Fac Appl Sci, Ho Chi Minh City 70000, Vietnam.;[Brindhadevi, Kathirvel] Saveetha Univ, Saveetha Inst Med & Tech Sci, Saveetha Dent Coll, Ctr Transdisciplinary Res CFTR,Dept Pharmacol, Chennai, India.
通讯机构：
[Nguyen Thuy Lan Chi; Deyi Yuan] S;School of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China<&wdkj&>School of Engineering and Technology, Van Lang University, Ho Chi Minh City, Viet Nam
通讯机构：
[Wenfang Gong; Deyi Yuan] K;Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of the Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
摘要：
Flavonoids, the effective material basis for the anti-thrombotic, anti-myocardial ischemia, and anti-dementia drug system framework, are one class of the main bioactive compounds in tea-oil Camellia. However, the molecular mechanism of the transcription regulation of flavonoid biosynthesis in tea-oil Camellia has not been fully investigated. Camellia lanceoleosa (C. lanceoleosa) is a diploid species of section Oleifera with genomic information, which has high value in scientific research and application. To comprehend the molecular mechanism of flavonoid biosynthesis in C. lanceoleosa, five different tissues (roots, stems, leaves, flower buds, and seeds) were used to perform an integrated analysis of the metabolome and transcriptome. Overall, 1,437 metabolites were identified and quantified, among which 488 common metabolites and 92 tissue-specific metabolites were detected in different tissues of C. lanceoleosa. Notably, the most abundant metabolite class was the flavonoids in the detected tissues of C. lanceoleosa. Furthermore, the differential metabolites and genes were also mainly enriched in flavonoid biosynthesis. A total of 145 differentially accumulated flavonoids and 65 differentially expressed structural genes were found within the biosynthesis of flavonoid in C. lanceoleosa. The expression patterns of most genes were consistent with the flavonoid accumulation patterns in the corresponding pathways. Using weighted gene coexpression network analysis, five gene modules and several candidate hub genes involved in flavonoid biosynthesis were investigated in different tissues of C. lanceoleosa, these genes included differentially expressed structural genes (PAL, CHS, DFR, and ANR) and transcription factors (bHLHs, MYBs, WRKYs, NACs, and SPL6). These results provide useful genetic resources for studying the molecular insights into the regulatory network of flavonoid biosynthesis in C. lanceoleos.
摘要：
The INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) controls floral organ abscission in plants. IDA belongs to IDA-LIKE (IDL) gene family that is involved in regulation of Arabidopsis development. Herein, we identified three genes, CoIDA1, CoIDA2 and CoIDA3 in Camellia oleifera (Camellia oleifera Abel. cv. Huashuo) and suggested their involvement in the regulation of fruits abscission. The full-length cDNA sequences of CoIDA1, CoIDA2 and CoIDA3 were of 207 bp, 276 bp and 273 bp, encoding proteins of 68, 91 and 90 amino acids, respectively. These CoIDA genes were single exon genes (SEGs) with a conserved extended PIP motif (EPIP) at C-terminal that has been implicated to play an important role in governing protein function for enhanced flower abortion rate. The highest expression of CoIDA1 was in young peduncles and the lowest in young fruits. However, the highest expressions of CoIDA2 and CoIDA3 were both in young roots, and the lowest in young fruits. The expressions of CoIDA1 and CoIDA2 significantly increased in abscission zones (AZs) of both abnormal fruits (AF) and ethephon treated fruits (ETH-F) with respect to normal fruits (NF), which suggest that CoIDA1 and CoIDA2 genes are related to fruits abscission in C. oleifera. This study provided a preliminary understanding about CoIDA genes which could lead to their detailed functional analysis and utilization for improving C. oleifera yield potential.
通讯机构：
[Xiaoling Ma; Deyi Yuan] K;Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education and the Key Laboratory of Non-Wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
摘要：
<jats:p>
Immature fruit abscission is a key limiting factor in
<jats:italic>Camellia oleifera</jats:italic>
Abel. (
<jats:italic>C. oleifera</jats:italic>
) yield. Ethylene is considered to be an important phytohormone in regulating fruit abscission. However, the molecular mechanism of ethylene in regulating fruit abscission in
<jats:italic>C. oleifera</jats:italic>
has not yet been studied. Here, we found that the 1-aminocyclopropane-1-carboxylic acid (ACC) content was significantly increased in the abscission zones (AZs) of abnormal fruits (AF) which were about to abscise when compared with normal fruits (NF) in
<jats:italic>C. oleifera</jats:italic>
‘Huashuo’. Furthermore, exogenous ethephon treatment stimulated fruit abscission. The cumulative rates of fruit abscission in ethephon-treated fruits (ETH-F) on the 4th (35.0%), 8th (48.7%) and 16th (57.7%) days after treatment (DAT) were significantly higher than the control. The ACC content and 1-aminocyclopropane-1-carboxylate oxidase (ACO) activity in AZs of ETH-F were also significantly increased when compared with NF on the 4th and 8th DAT.
<jats:italic>CoACO1</jats:italic>
and
<jats:italic>CoACO2</jats:italic>
were isolated in
<jats:italic>C. oleifera</jats:italic>
for the first time. The expressions of
<jats:italic>CoACO1</jats:italic>
and
<jats:italic>CoACO2</jats:italic>
were considerably upregulated in AZs of AF and ETH-F. This study suggested that ethylene played an important role in immature fruit abscission of
<jats:italic>C. oleifera</jats:italic>
and the two
<jats:italic>CoACOs</jats:italic>
were the critical genes involved in ethylene's regulatory role.
</jats:p>
作者机构：
[袁德义] College of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China;[尚忠海; 丁鑫; 孙萌] Henan Academy of Forestry, Zhengzhou, 450008, China;[程建明] Henan Kalefu Horticulture Limited Company, Zhengzhou, 450000, China;[沈植国] College of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China, Henan Academy of Forestry, Zhengzhou, 450008, China
通讯机构：
[SHANG, Z.] H;Henan Academy of ForestryChina
通讯机构：
[Zhiqiang Han] T;The Laboratory of Forestry Genetics, Central South University of Forestry and Technology, Hunan, China<&wdkj&>The College of Forestry, Central South University of Forestry and Technology, Hunan, China
摘要：
Camellia oleifera is believed to exhibit a complex intraspecific polyploidy phenomenon. Abnormal microsporogenesis can promote the formation of unreduced gametes in plants and lead to sexual polyploidy, so it is hypothesized that improper meiosis probably results in the formation of natural polyploidy in Camellia oleifera. In this study, based on the cytological observation of meiosis in pollen mother cells (PMCs), we found natural 2n pollen for the first time in Camellia oleifera, which may lead to the formation of natural polyploids by sexual polyploidization. Additionally, abnormal cytological behaviour during meiosis, including univalent chromosomes, extraequatorial chromosomes, early segregation, laggard chromosomes, chromosome stickiness, asynchronous meiosis and deviant cytokinesis (monad, dyads, triads), was observed, which could be the cause of 2n pollen formation. Moreover, we confirmed a relationship among the length-width ratio of flower buds, stylet length and microsporogenesis. This result suggested that we can immediately determine the microsporogenesis stages by phenotypic characteristics, which may be applicable to breeding advanced germplasm in Camellia oleifera.
